<?php

/**
 * Basic sort handler for dates.
 *
 * This handler enables granularity, which is the ability to make dates
 * equivalent based upon nearness.
 *
 * @ingroup views_sort_handlers
 */
class views_handler_sort_date extends views_handler_sort {

    function option_definition() {
        $options = parent::option_definition();

        $options['granularity'] = array('default' => 'second');

        return $options;
    }

    function options_form(&$form, &$form_state) {
        parent::options_form($form, $form_state);

        $form['granularity'] = array(
            '#type' => 'radios',
            '#title' => t('Granularity'),
            '#options' => array(
                'second' => t('Second'),
                'minute' => t('Minute'),
                'hour' => t('Hour'),
                'day' => t('Day'),
                'month' => t('Month'),
                'year' => t('Year'),
            ),
            '#description' => t('The granularity is the smallest unit to use when determining whether two dates are the same; for example, if the granularity is "Year" then all dates in 1999, regardless of when they fall in 1999, will be considered the same date.'),
            '#default_value' => $this->options['granularity'],
        );
    }

    /**
     * Called to add the sort to a query.
     */
    function query() {
        $this->ensure_my_table();
        switch ($this->options['granularity']) {
            case 'second':
            default:
                $this->query->add_orderby($this->table_alias, $this->real_field, $this->options['order']);
                return;
            case 'minute':
                $formula = views_date_sql_format('YmdHi', "$this->table_alias.$this->real_field");
                break;
            case 'hour':
                $formula = views_date_sql_format('YmdH', "$this->table_alias.$this->real_field");
                break;
            case 'day':
                $formula = views_date_sql_format('Ymd', "$this->table_alias.$this->real_field");
                break;
            case 'month':
                $formula = views_date_sql_format('Ym', "$this->table_alias.$this->real_field");
                break;
            case 'year':
                $formula = views_date_sql_format('Y', "$this->table_alias.$this->real_field");
                break;
        }

        // Add the field.
        $this->query->add_orderby(NULL, $formula, $this->options['order'], $this->table_alias . '_' . $this->field . '_' . $this->options['granularity']);
    }

}
